Early onset of extremely aggressive, disruptive behavior has been identified as a marker of risk for later antisocial behavior and delinquency, making early behavior disorders among the best targets for prevention and early intervention efforts. Especially at risk are those children growing up in economically disadvantaged urban communities, for whom few intervention strategies have been successful. The present study follows consecutive admissions to an outpatient clinic that uses protocol-based behavioral interventions to treat extremely disruptive, preschool-aged children from predominantly socioeconomically disadvantaged communities. The goal of the present study is to identify factors that predict treatment completion and treatment outcome. Specific hypotheses are that (1) the behavioral interventions provided will produce reductions in children's problem behaviors, (2) caregivers' high pre-treatment use of correct behavior management strategies will predict persistence in treatment, and (3) contextual variables such as family history of psychopathology, family type, education, and income will predict both treatment completion and outcome. Data collection for this project is ongoing.